1. Technical Field
The present invention relates to a display device that output information of a pointed location in response to an operation of pointing a location, and a display control method.
2. Related Art
In related art, when a specific location of an image displayed by a display device such as a projector is pointed, a device of detecting the pointed location and displaying a pointer or the like in response to the detected location has been known (for example, see Patent Document 1 (Japanese Patent No. 4272904)). In this type of device, it is necessary to perform calibration so that the pointed location and the display location of the pointer or the like may coincide with each other. Generally, it is necessary to recalibrate at each time when the display condition changes in such a way that the display location of the displayed image changes, and lots of effort is required. Accordingly, in the device disclosed in Patent Document 1, when the display location changes, location change data indicating a location relationship between before and after the change is used, and thereby, the calibration is omitted.
The display device that detects and outputs the pointed location in the above described manner requires information on resolution of the displayed image. For example, the device disclosed in Patent Document 1 requires data indicating a relationship between before and after change when the display condition is changed, and determines resolution of the image by measuring the frequency of input horizontal and vertical synchronizing signals.
However, for example, information on correct resolution with respect to the input signals may not be obtained in the case where an image with unknown resolution is input or information on resolution is erroneously determined. Recently, the number of types of screen resolution has been ever increasing due to the widespread of digital broadcasting, the higher image quality of video contents, the diversification of display devices including portable equipment, or the like, and there are not a few cases where images with resolution not supported by the display devices is input. In the case, it is impossible to obtain information on resolution using a display device in related art, and there has been a problem that it is impossible to accurately obtain the location relationship between the pointed location and the image being displayed.